Phosphomonoesterases in the 2 sexes of the root-knot nematode,Meloidogyne lucknowica Singh, 1969

Summary The 2 phosphomonoesterases of the root-knot nematode were colorimetrically determined. Alkaline phosphatase activity was observed to be lower than the acid phosphatase activity. Sex related trends were clearly seen in the enzyme levels of the 2 sexes of thenematode. Alkaline phosphatase level differed 28.76%, while acid phosphatase level differed 60.36% in the 2 sexes.The authors are grateful to the Council of Science and Technology U.P. for the grant of a Research Scheme for these studies.     

An unexpectedly rapid decline in the X-ray afterglow emission of long gamma-ray bursts

'Long' gamma-ray bursts (GRBs) are commonly accepted to originate in the explosion of particularly massive stars, which give rise to highly relativistic jets. Inhomogeneities in the expanding flow result in internal shock waves that are believed to produce the gamma-rays we see. As the jet travels further outward into the surrounding circumstellar medium, 'external' shocks create the afterglow emission seen in the X-ray, optical and radio bands. Here we report observations of the early phases of the X-ray emission of five GRBs. Their X-ray light curves are characterised by a surprisingly rapid fall-off for the first few hundred seconds, followed by a less rapid decline lasting several hours. This steep decline, together with detailed spectral properties of two particular bursts, shows that violent shock interactions take place in the early jet outflows.     

BubR1 insufficiency causes early onset of aging-associated phenotypes and infertility in mice

Faithful segregation of replicated chromosomes is essential for maintenance of genetic stability and seems to be monitored by several mitotic checkpoints. Various components of these checkpoints have been identified in mammals, but their physiological relevance is largely unknown. Here we show that mutant mice with low levels of the spindle assembly checkpoint protein BubR1 develop progressive aneuploidy along with a variety of progeroid features, including short lifespan, cachectic dwarfism, lordokyphosis, cataracts, loss of subcutaneous fat and impaired wound healing. Graded reduction of BubR1 expression in mouse embryonic fibroblasts causes increased aneuploidy and senescence. Male and female mutant mice have defects in meiotic chromosome segregation and are infertile. Natural aging of wild-type mice is marked by decreased expression of BubR1 in multiple tissues, including testis and ovary. These results suggest a role for BubR1 in regulating aging and infertility.     

LMNA, encoding lamin A/C, is mutated in partial lipodystrophy

The lipodystrophies are a group of disorders characterized by the absence or reduction of subcutaneous adipose tissue. Partial lipodystrophy (PLD; MIM 151660) is an inherited condition in which a regional (trunk and limbs) loss of fat occurs during the peri-pubertal phase. Additionally, variable degrees of resistance to insulin action, together with a hyperlipidaemic state, may occur and simulate the metabolic features commonly associated with predisposition to atherosclerotic disease. The PLD locus has been mapped to chromosome 1q with no evidence of genetic heterogeneity. We, and others, have refined the location to a 5.3-cM interval between markers D1S305 and D1S1600 (refs 5, 6). Through a positional cloning approach we have identified five different missense mutations in LMNA among ten kindreds and three individuals with PLD. The protein product of LMNA is lamin A/C, which is a component of the nuclear envelope. Heterozygous mutations in LMNA have recently been identified in kindreds with the variant form of muscular dystrophy (MD) known as autosomal dominant Emery-Dreifuss MD (EDMD-AD; ref. 7) and dilated cardiomyopathy and conduction-system disease (CMD1A). As LMNA is ubiquitously expressed, the finding of site-specific amino acid substitutions in PLD, EDMD-AD and CMD1A reveals distinct functional domains of the lamin A/C protein required for the maintenance and integrity of different cell types.     

Photoperiodicity in the male rosefinch

Summary In male rosefinches (Carpodacus erythrinus) 12 h non-stimulatory photoperiods (12L12D) were as effective in stimulating testicular recrudescence, as were long photoperiods (18L6D) when presented as several intermittent symmetrical photoperiods. The results are discussed with regard to the hypothesis that photoperiodic effects in birds are mediated by circadian rhythms.This investigation was supported by a UGC grant to PDT.     

Histochemical localization of cholinesterases in the neural tissue of the pineal in the rhesus monkey.

The neural tissue of the monkey pineal contains both acetyl and butyryl cholinesterases. Acetylcholinesterase was localized in the cisternae of the nuclear membrane, rough endoplasmic reticulum, on the plasma membrane of the neurones, and on the axolemma of both non-myelinated and myelinated fibres. The enzyme was not found in the axosomatic or axo-dendritic synapses. It is therefore suggested that the pineal neurones have a cholinergic function rather than a cholinoceptive one.     

Development of lead-free multifunctional materials Bi(Co0.45Ti0.45Fe0.10)O3

A lead free multiferroic material,Bi(Co_(0.45)Ti_(0.45)Fe_(0.10))O_3(BCTF45/10)was synthesized by a solid-state reaction route at high temperatures.BCTF45/10 powder was prepared using appropriate raw maretials in oxide powders with methanol medium.As-prepared circular shaped pellets were sintered at 1053 K for 6 h to produce a compact form.Preliminary structural properties and elemental analysis were determined using X-ray diffraction and energy-dispersive X-ray spectroscopy techniques respectively at room temperature.The microstructure or surface morphology of the sintered sample was carried out by using field emission scanning electron microscope(FE-SEM).The XRD analysis shows that the compound exhibits the single-phase of orthorhombic symmetry.The average crystallite size estimated using the Scherrer's technique was found to be 30 nm.The influence of Co and Ti substitution(at Bi and Ti sites of Bi Fe O_3)on some physical and electrical properties of Bi Fe O_3was examined by using phase sensitive multimeter in a wide frequency and temperature ranges.The magnetic nature of the sample was studied using vibrating sample magnetometer.Study of room temperature magnetic hysteresis loop exhibits the enhanced ferromagnetic characteristic with saturation magnetization of 5.091 emu/g and coercive field of 0.213 k Oe respectively.The enhanced magnetic properties highlight various potential applications of Co/Ti doped BCTF45/10 materials.     

Enhancement of figure of merit (ZT) by doping Bi in Mg2Si for energy harvesting applications

Magnesium Silicide is one of the interesting thermoelectric materials known for relative abundance of its constituents, thermal stability, non-toxicity and environmental friendly nature. In this paper we have theoretically studied Bi doped Mg_2Si. The electronic structure calculations predict non-existence of the energy gap for Mg_2Si_(1-x)Bi_x with(0.125≤ x≤0.5). It has been found that the system with x=0.125 exhibits highest Seebeck coefficient and electrical conductivity. Due to low thermal conductivity at x=0.125, Mg_2Si_(0.875)Bi_(0.125) attained maximum value of dimensionless figure of merit 0.67 at 1200 K. With increase in concentration of Bi,the value of figure of merit decreases.     

Large-scale analysis of the yeast genome by transposon tagging and gene disruption

Economical methods by which gene function may be analysed on a genomic scale are relatively scarce. To fill this need, we have developed a transposon-tagging strategy for the genome-wide analysis of disruption phenotypes, gene expression and protein localization, and have applied this method to the large-scale analysis of gene function in the budding yeast Saccharomyces cerevisiae. Here we present the largest collection of defined yeast mutants ever generated within a single genetic background--a collection of over 11,000 strains, each carrying a transposon inserted within a region of the genome expressed during vegetative growth and/or sporulation. These insertions affect nearly 2,000 annotated genes, representing about one-third of the 6,200 predicted genes in the yeast genome. We have used this collection to determine disruption phenotypes for nearly 8,000 strains using 20 different growth conditions; the resulting data sets were clustered to identify groups of functionally related genes. We have also identified over 300 previously non-annotated open reading frames and analysed by indirect immunofluorescence over 1,300 transposon-tagged proteins. In total, our study encompasses over 260,000 data points, constituting the largest functional analysis of the yeast genome ever undertaken.